--- /dev/null
+// resolve.cc -- symbol resolution for gold
+
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include "elfcpp.h"
+#include "target.h"
+#include "object.h"
+#include "symtab.h"
+#include "plugin.h"
+
+namespace gold
+{
+
+// Symbol methods used in this file.
+
+// This symbol is being overridden by another symbol whose version is
+// VERSION. Update the VERSION_ field accordingly.
+
+inline void
+Symbol::override_version(const char* version)
+{
+ if (version == NULL)
+ {
+ // This is the case where this symbol is NAME/VERSION, and the
+ // version was not marked as hidden. That makes it the default
+ // version, so we create NAME/NULL. Later we see another symbol
+ // NAME/NULL, and that symbol is overriding this one. In this
+ // case, since NAME/VERSION is the default, we make NAME/NULL
+ // override NAME/VERSION as well. They are already the same
+ // Symbol structure. Setting the VERSION_ field to NULL ensures
+ // that it will be output with the correct, empty, version.
+ this->version_ = version;
+ }
+ else
+ {
+ // This is the case where this symbol is NAME/VERSION_ONE, and
+ // now we see NAME/VERSION_TWO, and NAME/VERSION_TWO is
+ // overriding NAME. If VERSION_ONE and VERSION_TWO are
+ // different, then this can only happen when VERSION_ONE is NULL
+ // and VERSION_TWO is not hidden.
+ gold_assert(this->version_ == version || this->version_ == NULL);
+ this->version_ = version;
+ }
+}
+
+// This symbol is being overidden by another symbol whose visibility
+// is VISIBILITY. Updated the VISIBILITY_ field accordingly.
+
+inline void
+Symbol::override_visibility(elfcpp::STV visibility)
+{
+ // The rule for combining visibility is that we always choose the
+ // most constrained visibility. In order of increasing constraint,
+ // visibility goes PROTECTED, HIDDEN, INTERNAL. This is the reverse
+ // of the numeric values, so the effect is that we always want the
+ // smallest non-zero value.
+ if (visibility != elfcpp::STV_DEFAULT)
+ {
+ if (this->visibility_ == elfcpp::STV_DEFAULT)
+ this->visibility_ = visibility;
+ else if (this->visibility_ > visibility)
+ this->visibility_ = visibility;
+ }
+}
+
+// Override the fields in Symbol.
+
+template<int size, bool big_endian>
+void
+Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym,
+ unsigned int st_shndx, bool is_ordinary,
+ Object* object, const char* version)
+{
+ gold_assert(this->source_ == FROM_OBJECT);
+ this->u_.from_object.object = object;
+ this->override_version(version);
+ this->u_.from_object.shndx = st_shndx;
+ this->is_ordinary_shndx_ = is_ordinary;
+ this->type_ = sym.get_st_type();
+ this->binding_ = sym.get_st_bind();
+ this->override_visibility(sym.get_st_visibility());
+ this->nonvis_ = sym.get_st_nonvis();
+ if (object->is_dynamic())
+ this->in_dyn_ = true;
+ else
+ this->in_reg_ = true;
+}
+
+// Override the fields in Sized_symbol.
+
+template<int size>
+template<bool big_endian>
+void
+Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym,
+ unsigned st_shndx, bool is_ordinary,
+ Object* object, const char* version)
+{
+ this->override_base(sym, st_shndx, is_ordinary, object, version);
+ this->value_ = sym.get_st_value();
+ this->symsize_ = sym.get_st_size();
+}
+
+// Override TOSYM with symbol FROMSYM, defined in OBJECT, with version
+// VERSION. This handles all aliases of TOSYM.
+
+template<int size, bool big_endian>
+void
+Symbol_table::override(Sized_symbol<size>* tosym,
+ const elfcpp::Sym<size, big_endian>& fromsym,
+ unsigned int st_shndx, bool is_ordinary,
+ Object* object, const char* version)
+{
+ tosym->override(fromsym, st_shndx, is_ordinary, object, version);
+ if (tosym->has_alias())
+ {
+ Symbol* sym = this->weak_aliases_[tosym];
+ gold_assert(sym != NULL);
+ Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
+ do
+ {
+ ssym->override(fromsym, st_shndx, is_ordinary, object, version);
+ sym = this->weak_aliases_[ssym];
+ gold_assert(sym != NULL);
+ ssym = this->get_sized_symbol<size>(sym);
+ }
+ while (ssym != tosym);
+ }
+}
+
+// The resolve functions build a little code for each symbol.
+// Bit 0: 0 for global, 1 for weak.
+// Bit 1: 0 for regular object, 1 for shared object
+// Bits 2-3: 0 for normal, 1 for undefined, 2 for common
+// This gives us values from 0 to 11.
+
+static const int global_or_weak_shift = 0;
+static const unsigned int global_flag = 0 << global_or_weak_shift;
+static const unsigned int weak_flag = 1 << global_or_weak_shift;
+
+static const int regular_or_dynamic_shift = 1;
+static const unsigned int regular_flag = 0 << regular_or_dynamic_shift;
+static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift;
+
+static const int def_undef_or_common_shift = 2;
+static const unsigned int def_flag = 0 << def_undef_or_common_shift;
+static const unsigned int undef_flag = 1 << def_undef_or_common_shift;
+static const unsigned int common_flag = 2 << def_undef_or_common_shift;
+
+// This convenience function combines all the flags based on facts
+// about the symbol.
+
+static unsigned int
+symbol_to_bits(elfcpp::STB binding, bool is_dynamic,
+ unsigned int shndx, bool is_ordinary, elfcpp::STT type)
+{
+ unsigned int bits;
+
+ switch (binding)
+ {
+ case elfcpp::STB_GLOBAL:
+ bits = global_flag;
+ break;
+
+ case elfcpp::STB_WEAK:
+ bits = weak_flag;
+ break;
+
+ case elfcpp::STB_LOCAL:
+ // We should only see externally visible symbols in the symbol
+ // table.
+ gold_error(_("invalid STB_LOCAL symbol in external symbols"));
+ bits = global_flag;
+
+ default:
+ // Any target which wants to handle STB_LOOS, etc., needs to
+ // define a resolve method.
+ gold_error(_("unsupported symbol binding"));
+ bits = global_flag;
+ }
+
+ if (is_dynamic)
+ bits |= dynamic_flag;
+ else
+ bits |= regular_flag;
+
+ switch (shndx)
+ {
+ case elfcpp::SHN_UNDEF:
+ bits |= undef_flag;
+ break;
+
+ case elfcpp::SHN_COMMON:
+ if (!is_ordinary)
+ bits |= common_flag;
+ break;
+
+ default:
+ if (type == elfcpp::STT_COMMON)
+ bits |= common_flag;
+ else if (!is_ordinary && Symbol::is_common_shndx(shndx))
+ bits |= common_flag;
+ else
+ bits |= def_flag;
+ break;
+ }
+
+ return bits;
+}
+
+// Resolve a symbol. This is called the second and subsequent times
+// we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the
+// section index for SYM, possibly adjusted for many sections.
+// IS_ORDINARY is whether ST_SHNDX is a normal section index rather
+// than a special code. ORIG_ST_SHNDX is the original section index,
+// before any munging because of discarded sections, except that all
+// non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is
+// the version of SYM.
+
+template<int size, bool big_endian>
+void
+Symbol_table::resolve(Sized_symbol<size>* to,
+ const elfcpp::Sym<size, big_endian>& sym,
+ unsigned int st_shndx, bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object, const char* version)
+{
+ if (parameters->target().has_resolve())
+ {
+ Sized_target<size, big_endian>* sized_target;
+ sized_target = parameters->sized_target<size, big_endian>();
+ sized_target->resolve(to, sym, object, version);
+ return;
+ }
+
+ if (!object->is_dynamic())
+ {
+ // Record that we've seen this symbol in a regular object.
+ to->set_in_reg();
+ }
+ else if (st_shndx == elfcpp::SHN_UNDEF
+ && (to->visibility() == elfcpp::STV_HIDDEN
+ || to->visibility() == elfcpp::STV_INTERNAL))
+ {
+ // A dynamic object cannot reference a hidden or internal symbol
+ // defined in another object.
+ gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"),
+ (to->visibility() == elfcpp::STV_HIDDEN
+ ? "hidden"
+ : "internal"),
+ to->demangled_name().c_str(),
+ to->object()->name().c_str(),
+ object->name().c_str());
+ return;
+ }
+ else
+ {
+ // Record that we've seen this symbol in a dynamic object.
+ to->set_in_dyn();
+ }
+
+ // Record if we've seen this symbol in a real ELF object (i.e., the
+ // symbol is referenced from outside the world known to the plugin).
+ if (object->pluginobj() == NULL)
+ to->set_in_real_elf();
+
+ // If we're processing replacement files, allow new symbols to override
+ // the placeholders from the plugin objects.
+ if (to->source() == Symbol::FROM_OBJECT)
+ {
+ Pluginobj* obj = to->object()->pluginobj();
+ if (obj != NULL
+ && parameters->options().plugins()->in_replacement_phase())
+ {
+ this->override(to, sym, st_shndx, is_ordinary, object, version);
+ return;
+ }
+ }
+
+ unsigned int frombits = symbol_to_bits(sym.get_st_bind(),
+ object->is_dynamic(),
+ st_shndx, is_ordinary,
+ sym.get_st_type());
+
+ bool adjust_common_sizes;
+ if (Symbol_table::should_override(to, frombits, object,
+ &adjust_common_sizes))
+ {
+ typename Sized_symbol<size>::Size_type tosize = to->symsize();
+
+ this->override(to, sym, st_shndx, is_ordinary, object, version);
+
+ if (adjust_common_sizes && tosize > to->symsize())
+ to->set_symsize(tosize);
+ }
+ else
+ {
+ if (adjust_common_sizes && sym.get_st_size() > to->symsize())
+ to->set_symsize(sym.get_st_size());
+ // The ELF ABI says that even for a reference to a symbol we
+ // merge the visibility.
+ to->override_visibility(sym.get_st_visibility());
+ }
+
+ // A new weak undefined reference, merging with an old weak
+ // reference, could be a One Definition Rule (ODR) violation --
+ // especially if the types or sizes of the references differ. We'll
+ // store such pairs and look them up later to make sure they
+ // actually refer to the same lines of code. (Note: not all ODR
+ // violations can be found this way, and not everything this finds
+ // is an ODR violation. But it's helpful to warn about.)
+ bool to_is_ordinary;
+ if (parameters->options().detect_odr_violations()
+ && sym.get_st_bind() == elfcpp::STB_WEAK
+ && to->binding() == elfcpp::STB_WEAK
+ && orig_st_shndx != elfcpp::SHN_UNDEF
+ && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF
+ && to_is_ordinary
+ && sym.get_st_size() != 0 // Ignore weird 0-sized symbols.
+ && to->symsize() != 0
+ && (sym.get_st_type() != to->type()
+ || sym.get_st_size() != to->symsize())
+ // C does not have a concept of ODR, so we only need to do this
+ // on C++ symbols. These have (mangled) names starting with _Z.
+ && to->name()[0] == '_' && to->name()[1] == 'Z')
+ {
+ Symbol_location fromloc
+ = { object, orig_st_shndx, sym.get_st_value() };
+ Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary),
+ to->value() };
+ this->candidate_odr_violations_[to->name()].insert(fromloc);
+ this->candidate_odr_violations_[to->name()].insert(toloc);
+ }
+}
+
+// Handle the core of symbol resolution. This is called with the
+// existing symbol, TO, and a bitflag describing the new symbol. This
+// returns true if we should override the existing symbol with the new
+// one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to
+// true if we should set the symbol size to the maximum of the TO and
+// FROM sizes. It handles error conditions.
+
+bool
+Symbol_table::should_override(const Symbol* to, unsigned int frombits,
+ Object* object, bool* adjust_common_sizes)
+{
+ *adjust_common_sizes = false;
+
+ unsigned int tobits;
+ if (to->source() == Symbol::IS_UNDEFINED)
+ tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true,
+ to->type());
+ else if (to->source() != Symbol::FROM_OBJECT)
+ tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false,
+ to->type());
+ else
+ {
+ bool is_ordinary;
+ unsigned int shndx = to->shndx(&is_ordinary);
+ tobits = symbol_to_bits(to->binding(),
+ to->object()->is_dynamic(),
+ shndx,
+ is_ordinary,
+ to->type());
+ }
+
+ // FIXME: Warn if either but not both of TO and SYM are STT_TLS.
+
+ // We use a giant switch table for symbol resolution. This code is
+ // unwieldy, but: 1) it is efficient; 2) we definitely handle all
+ // cases; 3) it is easy to change the handling of a particular case.
+ // The alternative would be a series of conditionals, but it is easy
+ // to get the ordering wrong. This could also be done as a table,
+ // but that is no easier to understand than this large switch
+ // statement.
+
+ // These are the values generated by the bit codes.
+ enum
+ {
+ DEF = global_flag | regular_flag | def_flag,
+ WEAK_DEF = weak_flag | regular_flag | def_flag,
+ DYN_DEF = global_flag | dynamic_flag | def_flag,
+ DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag,
+ UNDEF = global_flag | regular_flag | undef_flag,
+ WEAK_UNDEF = weak_flag | regular_flag | undef_flag,
+ DYN_UNDEF = global_flag | dynamic_flag | undef_flag,
+ DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag,
+ COMMON = global_flag | regular_flag | common_flag,
+ WEAK_COMMON = weak_flag | regular_flag | common_flag,
+ DYN_COMMON = global_flag | dynamic_flag | common_flag,
+ DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag
+ };
+
+ switch (tobits * 16 + frombits)
+ {
+ case DEF * 16 + DEF:
+ // Two definitions of the same symbol.
+
+ // If either symbol is defined by an object included using
+ // --just-symbols, then don't warn. This is for compatibility
+ // with the GNU linker. FIXME: This is a hack.
+ if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols())
+ || object->just_symbols())
+ return false;
+
+ // FIXME: Do a better job of reporting locations.
+ gold_error(_("%s: multiple definition of %s"),
+ object != NULL ? object->name().c_str() : _("command line"),
+ to->demangled_name().c_str());
+ gold_error(_("%s: previous definition here"),
+ (to->source() == Symbol::FROM_OBJECT
+ ? to->object()->name().c_str()
+ : _("command line")));
+ return false;
+
+ case WEAK_DEF * 16 + DEF:
+ // We've seen a weak definition, and now we see a strong
+ // definition. In the original SVR4 linker, this was treated as
+ // a multiple definition error. In the Solaris linker and the
+ // GNU linker, a weak definition followed by a regular
+ // definition causes the weak definition to be overridden. We
+ // are currently compatible with the GNU linker. In the future
+ // we should add a target specific option to change this.
+ // FIXME.
+ return true;
+
+ case DYN_DEF * 16 + DEF:
+ case DYN_WEAK_DEF * 16 + DEF:
+ // We've seen a definition in a dynamic object, and now we see a
+ // definition in a regular object. The definition in the
+ // regular object overrides the definition in the dynamic
+ // object.
+ return true;
+
+ case UNDEF * 16 + DEF:
+ case WEAK_UNDEF * 16 + DEF:
+ case DYN_UNDEF * 16 + DEF:
+ case DYN_WEAK_UNDEF * 16 + DEF:
+ // We've seen an undefined reference, and now we see a
+ // definition. We use the definition.
+ return true;
+
+ case COMMON * 16 + DEF:
+ case WEAK_COMMON * 16 + DEF:
+ case DYN_COMMON * 16 + DEF:
+ case DYN_WEAK_COMMON * 16 + DEF:
+ // We've seen a common symbol and now we see a definition. The
+ // definition overrides. FIXME: We should optionally issue, version a
+ // warning.
+ return true;
+
+ case DEF * 16 + WEAK_DEF:
+ case WEAK_DEF * 16 + WEAK_DEF:
+ // We've seen a definition and now we see a weak definition. We
+ // ignore the new weak definition.
+ return false;
+
+ case DYN_DEF * 16 + WEAK_DEF:
+ case DYN_WEAK_DEF * 16 + WEAK_DEF:
+ // We've seen a dynamic definition and now we see a regular weak
+ // definition. The regular weak definition overrides.
+ return true;
+
+ case UNDEF * 16 + WEAK_DEF:
+ case WEAK_UNDEF * 16 + WEAK_DEF:
+ case DYN_UNDEF * 16 + WEAK_DEF:
+ case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
+ // A weak definition of a currently undefined symbol.
+ return true;
+
+ case COMMON * 16 + WEAK_DEF:
+ case WEAK_COMMON * 16 + WEAK_DEF:
+ // A weak definition does not override a common definition.
+ return false;
+
+ case DYN_COMMON * 16 + WEAK_DEF:
+ case DYN_WEAK_COMMON * 16 + WEAK_DEF:
+ // A weak definition does override a definition in a dynamic
+ // object. FIXME: We should optionally issue a warning.
+ return true;
+
+ case DEF * 16 + DYN_DEF:
+ case WEAK_DEF * 16 + DYN_DEF:
+ case DYN_DEF * 16 + DYN_DEF:
+ case DYN_WEAK_DEF * 16 + DYN_DEF:
+ // Ignore a dynamic definition if we already have a definition.
+ return false;
+
+ case UNDEF * 16 + DYN_DEF:
+ case WEAK_UNDEF * 16 + DYN_DEF:
+ case DYN_UNDEF * 16 + DYN_DEF:
+ case DYN_WEAK_UNDEF * 16 + DYN_DEF:
+ // Use a dynamic definition if we have a reference.
+ return true;
+
+ case COMMON * 16 + DYN_DEF:
+ case WEAK_COMMON * 16 + DYN_DEF:
+ case DYN_COMMON * 16 + DYN_DEF:
+ case DYN_WEAK_COMMON * 16 + DYN_DEF:
+ // Ignore a dynamic definition if we already have a common
+ // definition.
+ return false;
+
+ case DEF * 16 + DYN_WEAK_DEF:
+ case WEAK_DEF * 16 + DYN_WEAK_DEF:
+ case DYN_DEF * 16 + DYN_WEAK_DEF:
+ case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF:
+ // Ignore a weak dynamic definition if we already have a
+ // definition.
+ return false;
+
+ case UNDEF * 16 + DYN_WEAK_DEF:
+ case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
+ case DYN_UNDEF * 16 + DYN_WEAK_DEF:
+ case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF:
+ // Use a weak dynamic definition if we have a reference.
+ return true;
+
+ case COMMON * 16 + DYN_WEAK_DEF:
+ case WEAK_COMMON * 16 + DYN_WEAK_DEF:
+ case DYN_COMMON * 16 + DYN_WEAK_DEF:
+ case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF:
+ // Ignore a weak dynamic definition if we already have a common
+ // definition.
+ return false;
+
+ case DEF * 16 + UNDEF:
+ case WEAK_DEF * 16 + UNDEF:
+ case DYN_DEF * 16 + UNDEF:
+ case DYN_WEAK_DEF * 16 + UNDEF:
+ case UNDEF * 16 + UNDEF:
+ // A new undefined reference tells us nothing.
+ return false;
+
+ case WEAK_UNDEF * 16 + UNDEF:
+ case DYN_UNDEF * 16 + UNDEF:
+ case DYN_WEAK_UNDEF * 16 + UNDEF:
+ // A strong undef overrides a dynamic or weak undef.
+ return true;
+
+ case COMMON * 16 + UNDEF:
+ case WEAK_COMMON * 16 + UNDEF:
+ case DYN_COMMON * 16 + UNDEF:
+ case DYN_WEAK_COMMON * 16 + UNDEF:
+ // A new undefined reference tells us nothing.
+ return false;
+
+ case DEF * 16 + WEAK_UNDEF:
+ case WEAK_DEF * 16 + WEAK_UNDEF:
+ case DYN_DEF * 16 + WEAK_UNDEF:
+ case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
+ case UNDEF * 16 + WEAK_UNDEF:
+ case WEAK_UNDEF * 16 + WEAK_UNDEF:
+ case DYN_UNDEF * 16 + WEAK_UNDEF:
+ case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
+ case COMMON * 16 + WEAK_UNDEF:
+ case WEAK_COMMON * 16 + WEAK_UNDEF:
+ case DYN_COMMON * 16 + WEAK_UNDEF:
+ case DYN_WEAK_COMMON * 16 + WEAK_UNDEF:
+ // A new weak undefined reference tells us nothing.
+ return false;
+
+ case DEF * 16 + DYN_UNDEF:
+ case WEAK_DEF * 16 + DYN_UNDEF:
+ case DYN_DEF * 16 + DYN_UNDEF:
+ case DYN_WEAK_DEF * 16 + DYN_UNDEF:
+ case UNDEF * 16 + DYN_UNDEF:
+ case WEAK_UNDEF * 16 + DYN_UNDEF:
+ case DYN_UNDEF * 16 + DYN_UNDEF:
+ case DYN_WEAK_UNDEF * 16 + DYN_UNDEF:
+ case COMMON * 16 + DYN_UNDEF:
+ case WEAK_COMMON * 16 + DYN_UNDEF:
+ case DYN_COMMON * 16 + DYN_UNDEF:
+ case DYN_WEAK_COMMON * 16 + DYN_UNDEF:
+ // A new dynamic undefined reference tells us nothing.
+ return false;
+
+ case DEF * 16 + DYN_WEAK_UNDEF:
+ case WEAK_DEF * 16 + DYN_WEAK_UNDEF:
+ case DYN_DEF * 16 + DYN_WEAK_UNDEF:
+ case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF:
+ case UNDEF * 16 + DYN_WEAK_UNDEF:
+ case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
+ case DYN_UNDEF * 16 + DYN_WEAK_UNDEF:
+ case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
+ case COMMON * 16 + DYN_WEAK_UNDEF:
+ case WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
+ case DYN_COMMON * 16 + DYN_WEAK_UNDEF:
+ case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
+ // A new weak dynamic undefined reference tells us nothing.
+ return false;
+
+ case DEF * 16 + COMMON:
+ // A common symbol does not override a definition.
+ return false;
+
+ case WEAK_DEF * 16 + COMMON:
+ case DYN_DEF * 16 + COMMON:
+ case DYN_WEAK_DEF * 16 + COMMON:
+ // A common symbol does override a weak definition or a dynamic
+ // definition.
+ return true;
+
+ case UNDEF * 16 + COMMON:
+ case WEAK_UNDEF * 16 + COMMON:
+ case DYN_UNDEF * 16 + COMMON:
+ case DYN_WEAK_UNDEF * 16 + COMMON:
+ // A common symbol is a definition for a reference.
+ return true;
+
+ case COMMON * 16 + COMMON:
+ // Set the size to the maximum.
+ *adjust_common_sizes = true;
+ return false;
+
+ case WEAK_COMMON * 16 + COMMON:
+ // I'm not sure just what a weak common symbol means, but
+ // presumably it can be overridden by a regular common symbol.
+ return true;
+
+ case DYN_COMMON * 16 + COMMON:
+ case DYN_WEAK_COMMON * 16 + COMMON:
+ // Use the real common symbol, but adjust the size if necessary.
+ *adjust_common_sizes = true;
+ return true;
+
+ case DEF * 16 + WEAK_COMMON:
+ case WEAK_DEF * 16 + WEAK_COMMON:
+ case DYN_DEF * 16 + WEAK_COMMON:
+ case DYN_WEAK_DEF * 16 + WEAK_COMMON:
+ // Whatever a weak common symbol is, it won't override a
+ // definition.
+ return false;
+
+ case UNDEF * 16 + WEAK_COMMON:
+ case WEAK_UNDEF * 16 + WEAK_COMMON:
+ case DYN_UNDEF * 16 + WEAK_COMMON:
+ case DYN_WEAK_UNDEF * 16 + WEAK_COMMON:
+ // A weak common symbol is better than an undefined symbol.
+ return true;
+
+ case COMMON * 16 + WEAK_COMMON:
+ case WEAK_COMMON * 16 + WEAK_COMMON:
+ case DYN_COMMON * 16 + WEAK_COMMON:
+ case DYN_WEAK_COMMON * 16 + WEAK_COMMON:
+ // Ignore a weak common symbol in the presence of a real common
+ // symbol.
+ return false;
+
+ case DEF * 16 + DYN_COMMON:
+ case WEAK_DEF * 16 + DYN_COMMON:
+ case DYN_DEF * 16 + DYN_COMMON:
+ case DYN_WEAK_DEF * 16 + DYN_COMMON:
+ // Ignore a dynamic common symbol in the presence of a
+ // definition.
+ return false;
+
+ case UNDEF * 16 + DYN_COMMON:
+ case WEAK_UNDEF * 16 + DYN_COMMON:
+ case DYN_UNDEF * 16 + DYN_COMMON:
+ case DYN_WEAK_UNDEF * 16 + DYN_COMMON:
+ // A dynamic common symbol is a definition of sorts.
+ return true;
+
+ case COMMON * 16 + DYN_COMMON:
+ case WEAK_COMMON * 16 + DYN_COMMON:
+ case DYN_COMMON * 16 + DYN_COMMON:
+ case DYN_WEAK_COMMON * 16 + DYN_COMMON:
+ // Set the size to the maximum.
+ *adjust_common_sizes = true;
+ return false;
+
+ case DEF * 16 + DYN_WEAK_COMMON:
+ case WEAK_DEF * 16 + DYN_WEAK_COMMON:
+ case DYN_DEF * 16 + DYN_WEAK_COMMON:
+ case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON:
+ // A common symbol is ignored in the face of a definition.
+ return false;
+
+ case UNDEF * 16 + DYN_WEAK_COMMON:
+ case WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
+ case DYN_UNDEF * 16 + DYN_WEAK_COMMON:
+ case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
+ // I guess a weak common symbol is better than a definition.
+ return true;
+
+ case COMMON * 16 + DYN_WEAK_COMMON:
+ case WEAK_COMMON * 16 + DYN_WEAK_COMMON:
+ case DYN_COMMON * 16 + DYN_WEAK_COMMON:
+ case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON:
+ // Set the size to the maximum.
+ *adjust_common_sizes = true;
+ return false;
+
+ default:
+ gold_unreachable();
+ }
+}
+
+// A special case of should_override which is only called for a strong
+// defined symbol from a regular object file. This is used when
+// defining special symbols.
+
+bool
+Symbol_table::should_override_with_special(const Symbol* to)
+{
+ bool adjust_common_sizes;
+ unsigned int frombits = global_flag | regular_flag | def_flag;
+ bool ret = Symbol_table::should_override(to, frombits, NULL,
+ &adjust_common_sizes);
+ gold_assert(!adjust_common_sizes);
+ return ret;
+}
+
+// Override symbol base with a special symbol.
+
+void
+Symbol::override_base_with_special(const Symbol* from)
+{
+ gold_assert(this->name_ == from->name_ || this->has_alias());
+
+ this->source_ = from->source_;
+ switch (from->source_)
+ {
+ case FROM_OBJECT:
+ this->u_.from_object = from->u_.from_object;
+ break;
+ case IN_OUTPUT_DATA:
+ this->u_.in_output_data = from->u_.in_output_data;
+ break;
+ case IN_OUTPUT_SEGMENT:
+ this->u_.in_output_segment = from->u_.in_output_segment;
+ break;
+ case IS_CONSTANT:
+ case IS_UNDEFINED:
+ break;
+ default:
+ gold_unreachable();
+ break;
+ }
+
+ this->override_version(from->version_);
+ this->type_ = from->type_;
+ this->binding_ = from->binding_;
+ this->override_visibility(from->visibility_);
+ this->nonvis_ = from->nonvis_;
+
+ // Special symbols are always considered to be regular symbols.
+ this->in_reg_ = true;
+
+ if (from->needs_dynsym_entry_)
+ this->needs_dynsym_entry_ = true;
+ if (from->needs_dynsym_value_)
+ this->needs_dynsym_value_ = true;
+
+ // We shouldn't see these flags. If we do, we need to handle them
+ // somehow.
+ gold_assert(!from->is_target_special_ || this->is_target_special_);
+ gold_assert(!from->is_forwarder_);
+ gold_assert(!from->has_plt_offset_);
+ gold_assert(!from->has_warning_);
+ gold_assert(!from->is_copied_from_dynobj_);
+ gold_assert(!from->is_forced_local_);
+}
+
+// Override a symbol with a special symbol.
+
+template<int size>
+void
+Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from)
+{
+ this->override_base_with_special(from);
+ this->value_ = from->value_;
+ this->symsize_ = from->symsize_;
+}
+
+// Override TOSYM with the special symbol FROMSYM. This handles all
+// aliases of TOSYM.
+
+template<int size>
+void
+Symbol_table::override_with_special(Sized_symbol<size>* tosym,
+ const Sized_symbol<size>* fromsym)
+{
+ tosym->override_with_special(fromsym);
+ if (tosym->has_alias())
+ {
+ Symbol* sym = this->weak_aliases_[tosym];
+ gold_assert(sym != NULL);
+ Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
+ do
+ {
+ ssym->override_with_special(fromsym);
+ sym = this->weak_aliases_[ssym];
+ gold_assert(sym != NULL);
+ ssym = this->get_sized_symbol<size>(sym);
+ }
+ while (ssym != tosym);
+ }
+ if (tosym->binding() == elfcpp::STB_LOCAL
+ || ((tosym->visibility() == elfcpp::STV_HIDDEN
+ || tosym->visibility() == elfcpp::STV_INTERNAL)
+ && (tosym->binding() == elfcpp::STB_GLOBAL
+ || tosym->binding() == elfcpp::STB_WEAK)
+ && !parameters->options().relocatable()))
+ this->force_local(tosym);
+}
+
+// Instantiate the templates we need. We could use the configure
+// script to restrict this to only the ones needed for implemented
+// targets.
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
+Symbol_table::resolve<32, false>(
+ Sized_symbol<32>* to,
+ const elfcpp::Sym<32, false>& sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object,
+ const char* version);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Symbol_table::resolve<32, true>(
+ Sized_symbol<32>* to,
+ const elfcpp::Sym<32, true>& sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object,
+ const char* version);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Symbol_table::resolve<64, false>(
+ Sized_symbol<64>* to,
+ const elfcpp::Sym<64, false>& sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object,
+ const char* version);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Symbol_table::resolve<64, true>(
+ Sized_symbol<64>* to,
+ const elfcpp::Sym<64, true>& sym,
+ unsigned int st_shndx,
+ bool is_ordinary,
+ unsigned int orig_st_shndx,
+ Object* object,
+ const char* version);
+#endif
+
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Symbol_table::override_with_special<32>(Sized_symbol<32>*,
+ const Sized_symbol<32>*);
+#endif
+
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Symbol_table::override_with_special<64>(Sized_symbol<64>*,
+ const Sized_symbol<64>*);
+#endif
+
+} // End namespace gold.
projects / msp430-binutils.git / blobdiff